Articulated vehicles, such as articulated dump trucks (ADT's) are well-known in the art. For example, ADT's typically include a cab portion having a first frame supporting an operator cab, and a trailer portion having a second frame supporting a bin. The bin is configured to contain a load and is typically coupled to an actuator for angular movement relative to the second frame. The first frame and the second frame may be operably coupled through a universal joint including a pivot frame coupling for providing articulated movement of the first frame relative to the second frame about a vertical axis, and an oscillation frame coupling for providing oscillatory movement of the second frame relative to the first frame about a longitudinal axis. A first wheel assembly supports the first frame, and a second wheel assembly supports the second frame. The second wheel assembly includes a rotatably supported front wheel and a rotatably supported rear wheel. The front wheel and the rear wheel are coupled to a tandem or walking beam which, in turn, is pivotally coupled to the second frame by a tandem coupling. As such, the front wheel and the rear wheel are supported for pivoting movement about the tandem coupling to facilitate continuous wheel engagement over rough terrain.
ADT's may suffer from stability issues when not operated or loaded correctly. For example, instability may arise from the ADT being poorly loaded (too much weight too far forward on the bin), being near the end of the articulation range, and may be aggravated by operating in such a condition at relatively high speeds. Such stability issues may result in a “bin dump” condition where the center of gravity of the trailer portion moves outwardly over a line of action extending from the pivot frame coupling to the tandem coupling. In this condition, the trailer portion rolls over while the cab portion remains upright. While such a roll-over typically does not cause permanent equipment damage or operator injury, it causes the ADT and a related excavator to be out of commission until the trailer portion is uprighted.
According to one aspect of the present disclosure, a vehicle is provided including: a first frame; a first wheel assembly operably coupled to the first frame; a second frame defining a longitudinal axis; and a second wheel assembly operably coupled to the second frame. The second wheel assembly includes a tandem pivotally coupled to the second frame at a pivot coupling, a front wheel operably coupled to the tandem, and a rear wheel operably coupled to the tandem. The vehicle further includes a bin supported by the second frame and configured to support a load; and a frame coupling between the first frame and the second frame. The coupling is configured to provide pivoting movement between the first frame and the second frame about a vertical axis. The vehicle further includes a vehicle condition sensor configured to detect a condition of the vehicle; a controller in communication with the vehicle condition sensor; and a stabilizer operably coupled to the second frame and the tandem. The stabilizer includes a cylinder configured to restrict pivoting movement of the tandem in response to the condition sensed by the vehicle condition sensor. The stabilizer further including a valve controlling the supply of pressurized fluid to the cylinder.
According to another aspect of the present disclosure, a transport vehicle is provided that is configured to transport a load. The vehicle includes: a front vehicle frame assembly operably coupled to the front vehicle frame to provide rolling support for the front vehicle frame; and a trailer. The trailer includes a trailer frame and a trailer wheel assembly operably coupled to the trailer frame to provide rolling support for the trailer frame. The trailer wheel assembly includes a trailer tandem pivotally coupled to the trailer at a tandem pivot coupling, a front trailer tandem wheel rotatably coupled to the trailer tandem of the trailer wheel assembly to provide rolling support of the trailer tandem of the trailer wheel assembly, and a rear trailer tandem wheel rotatably coupled to the trailer tandem of the trailer wheel assembly to provide rolling support of the trailer tandem of the trailer wheel assembly. The trailer further includes a load bin supported by the trailer frame and configured to support a load transported by the transport vehicle; a center of gravity; and at least two lines of action defining a stability region therebetween. The vehicle further includes a transport vehicle frame coupling positioned between the front vehicle frame and the trailer frame and configured to provide pivoting movement between the front vehicle frame and the trailer frame about a vertical pivot axis. The vehicle further includes a transport vehicle condition sensor configured to detect a condition of the transport vehicle; a transport vehicle controller in communication with the transport vehicle condition sensor; and a transport vehicle stabilizer operably coupled to the trailer frame and the trailer tandem. The transport vehicle stabilizer includes a fluid cylinder configured to restrict pivoting movement of the transport vehicle tandem of the second transport vehicle wheel assembly in response to the condition of the transport vehicle sensed by the transport vehicle condition sensor, a fluid pump, the fluid pump being configured to supply fluid under pressure, and at least one fluid valve including a valve housing and a valve member positioned within the valve housing to control the flow of fluid. The stabilizer further includes at least one fluid line, the at least one fluid line communicating fluid between the fluid cylinder, the fluid pump, and the at least one fluid valve. The at least one fluid valve is configured to control the position of at least one of the lines of action to control the size of the area of the stability region.
According to another aspect of the present disclosure, a transport vehicle is provided that is configured to transport a load. The vehicle includes a first transport vehicle frame; a first transport vehicle wheel assembly operably coupled to the first transport vehicle frame to provide rolling support for the first transport vehicle frame; a second transport vehicle frame defining a longitudinal transport vehicle frame axis; and a second transport vehicle wheel assembly operably coupled to the second transport vehicle frame to provide rolling support for the second transport vehicle frame. The second transport vehicle wheel assembly includes a transport vehicle tandem pivotally coupled to the second transport vehicle frame at a tandem pivot coupling, a front tandem wheel rotatably coupled to the transport vehicle tandem of the second transport vehicle wheel assembly to provide rolling support of the transport vehicle tandem of the second transport vehicle wheel assembly, and a rear tandem wheel rotatably coupled to the transport vehicle tandem of the second transport vehicle wheel assembly to provide rolling support of the transport vehicle tandem of the second transport vehicle wheel assembly. The vehicle further includes a load bin supported by the second transport vehicle frame and configured to support a load transported by the transport vehicle; a transport vehicle frame coupling between the first transport vehicle frame and the second transport vehicle frame and configured to provide pivoting movement between the first transport vehicle frame and the second transport vehicle frame about a vertical pivot axis; a transport vehicle condition sensor configured to detect a condition of the transport vehicle; a transport vehicle controller in communication with the transport vehicle condition sensor; and a transport vehicle stabilizer operably coupled to the second transport vehicle frame and the transport vehicle tandem of the second transport vehicle wheel assembly. The transport vehicle stabilizer includes a fluid cylinder configured to restrict pivoting movement of the transport vehicle tandem of the second transport vehicle wheel assembly in response to the condition of the transport vehicle sensed by the transport vehicle condition sensor, a fluid pump configured to supply fluid under pressure, a fluid reservoir configured to hold the fluid, at least one fluid valve being configured to control the flow of fluid, and at least one fluid line. The at least one fluid line communicates fluid between the fluid cylinder, the fluid pump, the fluid reservoir, and the at least one fluid valve. The at least one fluid valve is configured to control the flow of fluid between the fluid pump and the fluid cylinder and the supply of fluid between the fluid reservoir and the fluid cylinder. The at least one fluid valve is configured to receive an input from the controller based on the transport vehicle condition of the transport vehicle sensed by the transport vehicle condition sensor to control the proportion of the fluid flowing through the at least one fluid line between the fluid pump and the fluid cylinder and the proportion of fluid flowing through the at least one fluid line between the fluid reservoir and the fluid cylinder.
Additional features and advantages of the present invention will become apparent to those skilled in the art upon consideration of the following detailed description of the illustrative embodiment exemplifying the best mode of carrying out the invention as presently perceived.